This study compiles information on the size distribution and reproductive patterns of five chondrichthyans and 10 bony species dwelling on the continental slope of the Central-Western Mediterranean (south-eastern Sardinian waters, depth 720–1890 m). The abundance of the relatively less numerous chondrichthyans was found to decrease with depth. Almost all chondrichthyan species had a long reproductive period throughout the year at all depths. In bony fishes, the upper bathymetric stratum (<1100 m) was dominated by species with continuous and seasonal (autumn-winter) spawning cycles. At intermediate and lower depths (>1100 m), continuous reproduction was the most common pattern. Both chondrichthyans and bony fishes exhibited large sizes at maturity and at first maturity (>75% and >60% of their maximum body length, respectively), supporting the hypothesis that most deep-sea fish populations are characterized by a delayed maturity, which makes them highly vulnerable to fishing pressure and over-exploitation. In some sharks, population partitioning was observed, according to life stage as a function of depth: adult/mature females occupied deeper habitats than males and juveniles. Conversely, Dipturus nidarosiensis female and male juveniles (>1100 m) were segregated from the adult/mature population, dwelling between 1000 and 1100 m. In four of the 10 bony fishes examined, we found a clear and significant predominance of females, particularly pronounced in Alepocephalus rostratus, which is clearly related to their K-reproductive strategy. The four key-selected species (Galeus melastomus, A. rostratus, Bathypterois mediterraneus and Trachyrincus scabrus), characterized by different reproductive strategies/modalities and feeding behaviours, were differently affected by depth and fluxes of organic matter (Particulate Organic Carbon concentration) from the photic zone towards the sea-bottom as a function of sex and life -stage.

这项研究汇编了居住在中西地中海大陆坡（南撒丁岛水域，深度720-1890 m）的大陆坡上的5种软骨鱼类和10种骨类物种的大小分布和生殖方式的信息。发现相对较少的软骨鱼类的丰度随深度而降低。几乎所有的软骨鱼类在全年所有深度都有很长的繁殖期。在骨鱼类中，上等深线层（<1100 m）以具有连续和季节性（秋季－冬季）产卵周期的物种为主。在中等深度和较低深度（> 1100 m），连续再现是最常见的模式。软骨鱼类和骨鱼类在成熟和首次成熟时均表现出较大的尺寸（分别超过其最大体长的75％和> 60％），支持以下假设：大多数深海鱼类种群的特征是延迟成熟，这使它们极易受到捕鱼压力和过度开发的影响。在某些鲨鱼中，根据生命阶段根据深度进行了种群划分：成年/成年雌性的栖息地比雄性和幼年的更深。反过来，从成年/成年种群中分离出尼古罗双翅目雌性和雄性幼体（> 1100 m），栖居在1000至1100 m之间。在所检查的10条骨鱼中，有4条发现了明显而显着的雌性优势，特别是在Alepocephalus rostratus中明显，这与它们的K繁殖策略有关。四个关键选择种（Galeus melastomus，A. rostratus，Bathypterois mediterraneus和Trachyrincus scabrus））以不同的生殖策略/方式和进食方式为特征，受性别和生命阶段的影响，受光区向海底的有机质的深度和通量（颗粒有机碳浓度）的变化程度不同。